In the context of what is disclosed in this document, a photodetector is a device capable of converting electromagnetic irradiation into an electrical quantity, such as voltage, current, resistance, etc. Typically, a wavelength of the electromagnetic irradiation is within a range that is visible to the human eye or adjacent to the visible wavelength range, such as infrared light or ultraviolet light. Nevertheless, it is also possible that a specific photodetector is configured to detect electromagnetic radiation in another wavelength range.
A single photodetector may be used for providing a single electrical signal indicating e.g. a brightness or intensity of an incident radiation. Another possible application of a photodetector is within image sensors, where a plurality of photodetectors are arranged in an array. Typically, a photodetector is responsive to a fixed or predetermined range of the wavelength.